From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Zyngier , Tomasz Nowicki , Christoffer Dall , Thomas Gleixner , Sasha Levin Subject: [PATCH 4.4 072/192] [PATCH 075/135] hrtimer: Catch illegal clockids Date: Mon, 12 Sep 2016 18:59:41 +0200 Message-Id: <20160912152201.960144502@linuxfoundation.org> In-Reply-To: <20160912152158.855601725@linuxfoundation.org> References: <20160912152158.855601725@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 9006a01829a50cfd6bbd4980910ed46e895e93d7 ] It is way too easy to take any random clockid and feed it to the hrtimer subsystem. At best, it gets mapped to a monotonic base, but it would be better to just catch illegal values as early as possible. This patch does exactly that, mapping illegal clockids to an illegal base index, and panicing when we detect the illegal condition. Signed-off-by: Marc Zyngier Cc: Tomasz Nowicki Cc: Christoffer Dall Link: http://lkml.kernel.org/r/1452879670-16133-3-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/time/hrtimer.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -94,6 +94,9 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, }; static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { + /* Make sure we catch unsupported clockids */ + [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, + [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, @@ -102,7 +105,9 @@ static const int hrtimer_clock_to_base_t static inline int hrtimer_clockid_to_base(clockid_t clock_id) { - return hrtimer_clock_to_base_table[clock_id]; + int base = hrtimer_clock_to_base_table[clock_id]; + BUG_ON(base == HRTIMER_MAX_CLOCK_BASES); + return base; } /*